The present invention relates to a heat insulating cover on an upwardly open cooling container, especially deep cooling container, with cover plates which cover the cooling chamber, abut against one another, and are placed on the upper edge of the cooling container.
In automatically operating storages cooling containers are used for storing and presenting of food. The food stored in them is maintained at different temperatures, for example up to -21.degree. C. and deeper. Due to the partially high temperature differences relative to the surrounding air and due to the open position of the food the deep cooling containers are characterized first of all by significant cold losses. For avoiding these losses which are very energy expensive and with consideration of a stepped open, not covered goods presentation, the only way to reduce these losses is to close the containers by suitable covers of insulating material during the night. This is conventional in many storages of food institutions.
In order to satisfy the operator of the storage for saving the energy in respective designs of the manufacturer, the cooling containers were provided with closing covers which are generally composed of a thick heat insulating layer of a synthetic plastic foam of several centimeters, with both side coatings of metal or synthetic plastic material, as well as with the corresponding edge trimming for fulfilling the hygiene requirements. These covers abut tightly near one another on the container edge and form an approximately tight surface for good heat insulating properties.
The disadvantage of this cover is that in the gaps between the abutting cover plates air moisture condensates from insides upwardly and forms icicles. When the cover plates are withdrawn individually from the cooling container edges, they fall on the food located underneath. As a result in many storages the night covering is not used to avoid damages to the goods presentation by icicles and similar phenomena.
Moreover, during the operation of such deep cooling containers, the cooling medium evaporator is iced due to the lower operational temperatures. This icing distorts the functions and the operation, and therefore it is required to defrost the evaporator with the use of additional energy and then again restore its operability.
In the deep cooling containers of the known type the moist air in the cooling chamber is circulated during defrosting of the goods to be cooled so that the portion of the moisture in the circulating air in relative short time forms ice on the surfaces of the evaporator.